Coolant light flashes on an off

Occasionallly the coolant light flashes on and off rapidly on my 2004 Pontiac Montana.the vehicle starts to stall, windows lock. everything goes haywire.What does this mean? I have checked the coolant levels and they are fine. coolant is clean

I have a 2003 Pontiac Montana. I came home in the evening and turned off my lights but
discovered the dashboard, parking lights and tails lights were still on when exiting the van. I
looked through ...